Dark Energy, Deceleration and the Universe’s Roller Coaster Ride

Dark Energy, Deceleration and the Universe’s Roller Coaster Ride

For the past five billion years, the expansion of the Universe has been speeding up, powered by the mysterious repulsive force known as “dark energy.” But thanks to a new technique for measuring the three-dimensional structure of the distant Universe, astronomers from the Sloan Digital Sky Survey have made the first measurement of the cosmic expansion rate just three billion years after the Big Bang.

“If we think of the Universe as a roller coaster, then today we are rushing downhill, gaining speed as we go,” says Nicolas Busca, one of the lead authors of a paper submitted to the journal Astronomy and Astrophysics. “Our new measurement tells us about the time when the Universe was climbing the hill – still being slowed by gravity.”